Lifting rotor blade attachment



Aug. 8, 1950. D, N. MEYl-:Rcs

' LIFTNG Ro'ron BLADE A'r'rAcx-MENT Filed May 29, 1947 v FL:

IN V EN TOR.

Patented Aug. 8, 1950 asian:

Lll'l'lNG IOTOB BLADE ATTACHMENT Donald N. Meyers,

menne allignlnen Pa., auignor, by

Philadelphia. tl, to lhlecki Helicopter Corporation, Morton. la., a corporation of Pennlylvania Application May 29, 1947, Scrlal'No. 751,309

This invention relates to rotary wing aircraft and more particularly to improvements in rootend fittings for rotary wing blades.

The principal object of this invention is to pro- Y vide a root-end fitting that is light in weight and permits quick adjustment of the angle of incidence of the blade.

Another object of the invention is to provide a root-end that may be quickly and easily attached to the blade, and detached therefrom.

Another object of this invention is to provide a root-end fitting that will transmit the centrifugal loads of a blade to the hub in an emci'ent manner.

Other objects and advantages will become apparent in the following specication when read in conjunction with the accompanying drawings in which:

Figure 1 is an'elevational view of a root-end of a blade without the root-end fitting.

Figure 2 is an elevational view of a root-end of .a blade with the root-end fitting partly assembled thereon.

Figure 3 is a cross-sectional view of a root-end of a blade with the root-end fitting completely assembled thereon.

The root-end tting is comprised of a housing Il having a. split portion i2 at the outer end thereof and a split bushing I3 adapted to t into the outer portion of the housing Il. the length of the split bushing exceeding twice the diameter of that portion of the spar which it engages as shown in Figure 3 of the drawings. A spacer member Il is positioned between the inner end of the housing ii and the spacer 2l. At the inner end of the blade spar 2l a sleeve i5 is welded thereto to form an abutment. Y This abutment can also be formed by a machine process if desired. Housing i I has the outer portion thereof bored to slide over the sleeve Ii and bushing I3. The inner portion is bored to a larger diameter to receive the shoulder portion I6 of the split bushing I3 and the spacer Il. .In the inner portion of the housing li is a hole I1 drilled therethrough to receive the drag or flapping hinge pin carried by the hub portion of the rotor not shown.

In assembling the root-end iitting the housing Il is iirst slipped over sleeve I and moved out on the blade spar 2l to the position shown in Figure 2. Next, the split bushing Ilia fitted on to the spar adjacent to the sleeve II after which the spacer member Il is slipped on the inner end of the blade spar. With the parts thus arranged the housing Il is moved back over the r cmu. (c1. 11o-1cm) split bushing i3 and the spacer I4 as shown in Figure 3. The split portion of the housing Ii is provided with two clamping ears It which are drilled to receive clamping bolts I9.

By referring to Figure 3 of the drawings it can be seen that the centrifugal force acting on the blade is transmitted to sleeve l5 which abuts against the split bushing I3 through which the forces are transmitted tothe housing ll. It will be noted that the spar 20 is well reinforced by the sleeve i5 and the bushing i3 at its rootend where high bending forces might be expected. l

Adjustment in the angle of incidence of the blade can easily be made by loosening the clamping bolts I9 which will permit the spar 2li to be rotated relative to the housing H until the proper setting is obtained at which time the clamping bolts i9 are tightened. This construction allows blades to be changed quickly and easily and permits blades to be exchanged without the use of new root-end fittings for each blade, as has been necessary in earlier blade designs.

While the foregoing is a description of the preferredembodiment of my invention, it is to be understood that various other forms and arrangements could be made without departing from the scope and spirit of my invention as disclosed herein and claimed in the following claims.

I claim:

1. Blade attachment means for aircraft sustaining rotors oomprising in combination, a tubular blade spar, an abutment on the inner portion of said spar, said abutment being of greater diameter than the spar, a split bushing circumferentially engaging said spar outboard of said abutment, the inner end of said bushing being in axial engagement with the outer end of said abutment, a shoulder formed on the inner portion o! said bushing, the outer portion of said bushing comprising a shank, the length of said shank being greater than twice the diameter of that portion of the spar it engages, a housing provided with attaching means, the outer portion of said housing being bored to slidably engage the shank of said bushing, the inner portion of the housing being bored for sliding engagement of the shoulder formed on said bushing and to form with the rst named bore an abutment for axial engagement with the shoulder of said bushing, the outer portion ofvsaid housing being split and provided with means to clamp the housing and bushing on the spar.

2. A blade attachment as set forth in claim l and including a, oollar positioned between the 4 UNITED STATES PATENTS inner end of said housing and the inner end ot Number Name Date said spar. l

3,v A blade attachment as set forth in claim 1 ggg'ggg uuign fpt' 133g and in which the clamping means is in- 5 1'995'460 pecker """"Maov'26 i935 wardly from the end 0f said housm 210471776 Hafner Jug 14 1936 DONALD N- MEYERS- 2,169,849 Pitcairn Aug. 151 1939 FOREIGN PATENTS Country Date Great Britain .---V July 6, 1933 REFERENCES cm1-:n

The following references are of record in the l0 Number le of this patent: 394,799 

